A Combined Multi-pulse Transmitting Circuit for Time-Domain Electromagnetic Detection

Time-domain transient electromagnetic method (TEM) typically employs two different multi-turn coils, the larger of which is used to transmit the time-varying current to generate a primary electromagnetic field and the other receives the secondary-field induced voltage from eddy currents of the subsurface conductors. A combined multi-pulse transmitting circuit for time-domain electromagnetic detection is proposed in this paper. The dual-pulse energy boosting and high-voltage clamping technology are employed in transmitting system to meet the requirements of large detection depth and high resolution in shallow strata simultaneously. The operation principles of the proposed topology are explained and the simplified control method is provided. Simulation results demonstrate that the circuit can generate high-quality combined current pulses for the highly inductive load. Extensive experiments verify that the proposed circuit and control method can improve the reliability and efficiency of the transmitting system and it is suitable for TEM application.